JPS6122731A - Charger - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field 1] The present invention relates to a charger using a DC-DC converter consisting of an inverter circuit.

[Background Art] In general, a DC-DC converter using a rectifier circuit that rectifies a commercial power source, an inverter circuit that converts the DC power output from the rectifier circuit into a DC power source for charging a storage battery, and a storage battery (for example, Ni - This type of charger is equipped with a charge display means for controlling the charging of the CD battery and displaying the state of charge, and the state of charge is displayed by turning on and off the light emitting diode. In many cases, when the charging control state is reached, a charging current is passed intermittently to lower the average charging current, and the light emitting diode is extinguished in synchronization with the intermittent charging current. By the way, conventional chargers only have a high-voltage power source that is a rectified commercial power source and a low-voltage power source that is slightly higher than the battery voltage (j, 25V). A light emitting diode (forward threshold voltage of 1
, 5 = 2.5V), the light-emitting diode was lit by lowering the voltage of the high-voltage power supply using a resistor.

However, there is a problem in that power loss due to this step-down resistor increases. In addition, in this type of system, the charging display means is formed of one light emitting diode, so if the blinking interval of the light emitting diode is short,
It becomes difficult to distinguish between blinking and continuous lighting, and there is a problem that it is difficult to distinguish between charging (blinking) and charging completion (continuous lighting).Also, if the interval between blinking of the light emitting diode is long, the light will turn off. There was a problem that sometimes people were under the illusion that it was not a malfunction.

[Invention 1] Objective 1 The present invention has been made in view of the above-mentioned 5α, and its purpose is to provide an inexpensive charger with less power loss.

Disclosure of the Invention 1 (Embodiment) Fig. 1 shows an embodiment of the present invention, in which 2 is a rectifier circuit that rectifies a commercial power source 1, and 3 is a rectifier circuit that uses the DC power output from the rectifier circuit 2 to charge a storage battery. 5 is a DC-r)C converter using an inverter circuit that converts it into a DC power source for use, and 5 is a charging completion detection circuit 6 that detects the battery voltage of a storage battery 9 to detect charging completion; This charging display means includes a lighting switching circuit 7 that switches lighting of two color light emitting diodes LD, , ID2 that display the status.

L and 8 are display power supply windings wound around the oscillation transformer OT of the inverter circuit separately from the charging windings #il, L, 2, and L3, and 8 is the display power supply circuit IQr.
This is a display power supply circuit that rectifies the induced voltages of - and 4 with a diode D to form a DC power supply for the charge display means 5.

In the figure, 4 is an oscillation circuit forming an impark circuit.

Figure 2 shows a specific circuit, and the rectifier circuit 2 is a diode.
It is formed by a dob 1/no DB, a cheek coil CH1, and a smoothing capacitor C3, and outputs a DC power source obtained by smoothing the commercial power source 1 in g current. The oscillation circuit 4 of the DC-DC converter 3 includes a switching transistor Q1, oscillation control transistors Q7 and QJ, and diodes D3 to D5, and a secondary winding I-5 of the oscillation transformer OT.
．． The storage battery 9 is charged with a DC power source whose output is rectified by a diode D1. In the figure, SW is a switch that controls power supply to a load M such as a motor.

The charging display means 5 includes a battery voltage detection circuit for detecting battery voltage, a timer circuit IC7 for controlling charging, and a transistor Q4. Q5, diode D is also formed by I]1, zener diode ZD, ~ZD1, and the DC voltage is determined based on the battery voltage.
- Controls the oscillation of the DC converter 3 to control the charging current according to the battery voltage, and also controls the charging state with two different colors.
Light emitting diodes1. , Dl, and T-D 2 are turned on.

The operation of the embodiment will be specifically explained below.

DC-DC converter 3 driven by rectifier circuit 2 output
is a so-called R, CC converter, and that!
The l1J1 works are as follows. Now, when a starting current flows through the resistor R1 to the transistor QI, the collector current of the transistor Q is one large winding I! of the oscillation transformer OT.
begins to flow through AL1, a voltage is induced in the feedback winding L, 3, the current due to this induced voltage is positively fed back to the base of transistor Q1, the collector current of transistor Q increases, and transistor Q1 rapidly Becomes fully on. The collector current of this transistor Q1 is the winding I,1
, the voltage generated across resistors R7 and R3 becomes the base emink voltage of transistor Q3\'T
When IE is exceeded, transistor Q:l turns on and bypasses the base current of transistor Q1, so transistor Q1 turns off. When the transistor Q1 is turned off, the current flowing through the windings 1 and 3 suddenly decreases, and the polarity of the voltage induced in the windings 1 and 3 is reversed, so that the transistor Q1 is reverse biased and continues to be turned off. Here, winding L2 is winding #i
IL: It is wound with the opposite polarity to l, and the transistor Q1
When the Wf7rl battery 9 is off, the Wf7rl battery 9 is charged through the diode D1. In this way, when the electromagnetic energy stored in winding #i[Ll is released through winding I7°,
Transistor Q1 returns to its initial state and conducts rlj c/ion. By repeating the operation 1-, the transistor Q1 is turned on and off, and the storage battery 9 is charged.

Next, the winding [-4 is 1] which constitutes the display power supply circuit 8 is the 7S wire which has nothing to do with the double oscillation operation, and in the embodiment, the winding ■7. When the charging current is flowing, the winding I1. than the induced voltage of
Generates a voltage (proportional to the number of turns). , this voltage 1f is rectified by the diode D, and is also slipped by the capacitor → no C (for each circuit of the charging display means 5 and the light emitting diode -r), 1. , r), , is formed.

Next, the operation of the charge display means 5 will be explained.

Now, while charging, the battery voltage is low, so the battery voltage detection circuit ■ pin of C1 is at H level, and transformer 7 transformer 0
4 is thin. Therefore, the Q of timer circuit IC7
) pin or l becomes level and timer times 1j'i l C
) is not working 1. Here, when the power supply voltage is applied to the timer circuit C2, it is automatically reset and the output of the pin is at I level, so the transistor Q2 is turned on and the voltage between the base and emitter of the transistor Q3 is turned on. The resistance is the resistor R2 (73), and if the current flowing through the 1-runnostar Q1 does not become large, the transistor Q
3 is not turned on, and state 1 is maintained where a large charging current flows. Also, at this time, the transistor Q is turned off at the same time, and a current flows through the resistor 17 to the red light emitting diode L D .
.

lights up to indicate that it is charging. On the other hand, when the charging power advances by °C and the battery voltage rises by 2', the battery voltage detection circuit IC becomes level 17 and the transistor Q
, is turned off, and the timer circuit IC2 operates. At this time, since the ■ pin of the timer circuit IC7 remains at the +-r level, charging continues with a large current. Next, when the time limit set in advance by the external time constant circuit of the timer circuit IC7 has elapsed, the ■bin of the timer circuit IC7 becomes level 17 and the transistor Q2 is turned off. The only resistance between the base and emitter is resistor R7 to reduce the charging current. At the same time, the lantern star Q is turned on, and the green light emitting diode L I) is turned on. Note that the sum of the forward threshold voltage Vdl of the light emitting diode Ll) and the Zener voltage Vz of the Zener diode ZD is the Zener voltage \l/ of the Zener diode 7,1')2, and the Zener voltage of the transistor Q, The transistor Q is set to be larger than the sum of the pace emitter voltage VII+-.

When the light-emitting diode 1-7D is turned on, the light emitting diode 1-7D becomes irritating. 3. Figure 3 is a time chart showing two-way operation, and figure (a) shows the battery voltage and charge. Current Tc, the same figure (I) to the same figure (d) are timer circuit I
The voltage waveforms of the ■, ■, and ■ bins of C2 in the same figure (e) show the lighting state of the light emitting diodes L, ID, and ID.

As mentioned above, in the embodiment, the charge indicator f father 5
Each circuit and light emitting diode LII), ,■,D.

A power source for driving is added to the oscillation transformer O'r of the inverter circuit of the DC-DC converter 3, and the winding ■1. Display power supply circuit 8 configured to rectify and smooth the voltage of
Since it is made of aluminum, power loss is reduced compared to the case where a step-down resistor is used as in the conventional example. In addition, the charging display means 5 is a two-color light emitting diode 1. , D 1, [, D
, the charging completion display can be displayed in bright W during charging, making it possible to reliably grasp the charging state. It goes without saying that the state of charge may be displayed in detail by using light emitting diodes of three or more colors.

[Effect of the invention 1] The present invention is a DC-DC system that uses a rectifier circuit that rectifies a commercial power source and an inverter circuit that converts the DC power output from the rectifier circuit into a DC power source for charging a storage battery.
In a charger equipped with a converter and a charging display means for controlling charging based on battery voltage and displaying charging status, the oscillation transformer of the inverter circuit is provided with a display power supply winding separate from the charging winding. It is equipped with a display power supply circuit that rectifies the induced voltage of the 8 wires for the display power supply to form a DC power supply for the photoelectric display means.The winding for the display power supply is connected to the oscillation transformer of the inverter circuit. By adding an appropriate voltage to light up one light emitting diode, the conventional voltage drop resistor is not required, which has the effect of reducing power loss. Since only a winding is added and no new step-down transformer is required, the cost increase can be reduced.

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram of an embodiment of the present invention, FIG. 2 is a specific circuit diagram of the same, and FIG. 1 is a commercial power supply, 2 is a rectifier circuit, 3 is a D(>D(converter), 5 is a charge display means, 6 is a charging completion circuit, 7 is a lighting switching circuit, 8 is a display power supply circuit, 9 is a storage battery, OT is the oscillation transformer, L is the display power supply winding, 1.!'),
, J-D, are light emitting diodes. . Agent Patent Attorney Ishi 1) Ai 7th Figure 1 Procedural Amendment (Method) February 13, 1985 Patent Application No. 142936 of 1988 2, Name of Invention Charger 3, Case of Person Making Amendment Related Patent Applicant Address 1048 Kadoma, Kadoma City, Osaka Name (
583) Matsushita Electric Works Company Representative Iku Kobayashi 4, Agent postal code 530 5, Amendment Order No. 111 October 9, 1982

Claims (3)

[Claims] (1) A DC-DC converter that uses a rectifier circuit that rectifies commercial power, an inverter circuit that converts the DC power output from the rectifier circuit into DC power for charging storage batteries, and controls charging based on the battery voltage. In a charger equipped with a charge display means for displaying the state of charge, the oscillation transformer of the inverter circuit is wound with a display power supply winding separate from the charging winding, and the induced voltage of the display power supply winding is What is claimed is: 1. A charger comprising a display power supply circuit that rectifies a DC power supply to form a DC power supply for a photoelectric display means. (2) The charger according to claim 1, wherein the charging display means is formed of light emitting diodes of two or more colors. (3) Claim 1 in which the charging display means is formed by a charging completion detection circuit that detects charging completion based on the battery voltage, and a lighting switching circuit that switches lighting of a light emitting diode based on the output of the charging detection circuit. Charger as described in section.